AVRDC: Recent Research October 2015

http://avrdc.org/biodegradable-plastic-mulch/

Mulching acts to control weeds, conserves soil moisture and increases soil temperature in tropical and sub-tropical environments which has positive effects on vegetable yield and quality. Plastic mulching material is now widely available in SE Asia at a relatively low cost. This cost is about 25 percent of that of new biodegradable plastic mulches which are now being tested owing to their ability to gradually degrade into water and CO2 without leaving harmful residues. The effects of a biodegradable polyester mulch and a standard polyethelene (PE) mulch on kangkong (Ipomoea aquatica) were compared in a first observational experiment conducted at AVRDC (The World Vegetable Center) headquarters in Taiwan from April to August 2014. After four weeks, degradation could be perceived in the biodegradable mulch; after 18 weeks, it had become torn into large pieces while the PE mulch remained intact. This resulted in apparently lower yields of kangkong as a broken mulching layer had a lower ability to retain soil water and heat, and to control weed growth. Implications for the environment and women’s labour are considered.

Figure: Chen WY, Keatinge JDH, Hughes J d’A. 2015. Biodegradable plastic mulch: a coming trade-off between women’s labour, production costs and environmental benefits? AGRICULTURE FOR DEVELOPMENT, 25:56-58.